RCA 1S5 NOS Vacuum Tube – Miniature Diode-Pentode in Original Box
The RCA 1S5 NOS Vacuum Tube represents a gold standard in 20th-century electronic engineering. Manufactured by the iconic Radio Corporation of America (RCA), this component is a 7-pin miniature diode-pentode specifically designed for use in battery-powered equipment, thanks to its low-consumption 1.4-volt filament.
Who Is It For and What Are Its Uses?
This component is intended for service technicians, vintage electronics restorers, radio enthusiasts, and audio purists. The 1S5 tube is traditionally used for two simultaneous functions within a circuit:
Diode Section: Acts as an AM Radio Frequency (RF) signal detector and provides voltage for Automatic Volume Control (AVC/AGC).
Pentode Section: Functions as a resistance-coupled audio-frequency (AF) amplifier, boosting the signal before sending it to the power output stage.
Condition and Performance Guarantee
We understand that trust is essential when purchasing NOS components. This RCA 1S5 NOS Vacuum Tube is not a replica; it is a genuine vintage component. It comes in its original cardboard box, which may show natural signs of age, adding to its historical value.
The integrity of its filaments and transconductance have been recently verified using a precision Kyoritsu tube tester, ensuring that the tube is electrically sound and ready for installation.
Manufacturer History: RCA (Radio Corporation of America)
Founded in 1919, RCA was the dominant corporation in the electronics and communications industry in the United States for more than five decades. The RCA Radiotron division pioneered the miniaturization of vacuum tubes, enabling the development of the first truly portable radios before the advent of the commercial transistor.
Owning an RCA tube means owning a piece of technological and industrial history.
Technical Information (Condensed Datasheet)
Tube Type: Diode-Pentode (Miniature Glass)
Base: B7G (7-Pin Miniature)
Filament Voltage (Vf): 1.4 Volts (DC)
Filament Current (If): 0.05 Amperes (50 mA)
Maximum Plate Voltage (Pentode): 90 Volts
Maximum Screen Grid Voltage (Grid 2): 90 Volts
Plate Dissipation: 0.15 Watts
Direct Equivalents: DAF91, 1FD9, ZD17, CV785.
(FAQ)
What Does It Mean That the Tube Is NOS?
NOS stands for New Old Stock. This means the tube was manufactured decades ago but was never installed or used in equipment. It is considered new old stock, having remained unused in original or surplus inventory for many years.What Equipment Is the RCA 1S5 NOS Vacuum Tube Compatible With?
It is compatible with most battery-powered portable radios from the 1940s and 1950s, including iconic models from Zenith (such as the Trans-Oceanic), Motorola, and RCA Victor that use 1.4V filament circuitry.How Can I Be Sure It Works If It Is So Old?
The tube has been tested for transconductance and shorts using a professional Kyoritsu tube tester, verifying that its electrical parameters meet factory specifications before shipping.Can It Replace a DAF91 Tube?
Yes, the 1S5 tube is electrically equivalent to and a direct replacement for the European DAF91 designation.
